Hem-folding attachment



Aug. 18, 1953 N. KNAUS ETAL 2,649,066

HEM-FOLDING ATTACHMENT Filed July 15, 1950 2 Sheets-Sheet 2 F M50236 [Vickolaas Knaus 5 7 and Wz'iwm Patented Aug. 18, 195?;

UNITED STATES PATENT TOFTFICE HEM-FOLDING ATTACHMENT Nicholaus Kna'us, cranforaana 'Aglies' Mil.-

lington, Clifton, N. J assignors to "TheSinger Manufacturing Company, Elizabeth, N. 'J., a corporation of New Jersey Application .luly 13, 195o, seiiaiN6. 173536 40mins. (01112 1 41) This invention relates to overedge sewing inachines and more particularly to means embodied therein for hem-folding the marginal portions of both fiat and tubular work-pieces and'for so presenting the folded work-pieces to the trimming and stitch-forming mechanisms that the proj ecting edge portion of each work-piece is trimmed off substantially in line with the fold and'the hem is secured to the body material by a blindstitch overedge seam.

A primary object of the invention is to provide an improved hem-folder which, although most efficient in operation, is at the same time adapted to be readily applied to a conventional type 'of sewing machine without the necessity of adding to the machine any special fittings in the way of brackets, bolts, clamps or the like.

A further object of the invention is to provide a hem-folder attachment which is adapted to rise and fall in response to the work-feeding'iriovements, thereby to facilitate the passage of the work therethrough.

Another object of the invention is to provide a hem-folder which is most inexpensive of manufacture.

With the above and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of apreferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings:

Fig. 1 represents a side elevation, partly in section, of a portion of an overedge sewing machine showing it fitted with the present improved hem-folder. H I

Fig. 2 represents a front elevation view, partly in section, of the machine disclosed inFig. 1.

Fig. 3 represents a sectional view through a hem-folded work-piece as it is being trimmed.

Fig. 4 represents a sectional View through a hem-folded work-piece during the needle penetrating operation. I I

Fig. 5 represents a finished hem-folded workpiece after the same has been opened into its flat position.

Fig. 6 represents a fragmentary top'plan view of the sewing machine fitted with the present hem-folder.

Fig. 7 represents a left-hand'elevationview or the presser-foot employed in the present machine, which presser-foot has incorporated thereinthe present hem-folder.

Fig. 8 'rep'resentsa'front"elevation view of the device disclosed in Fig. 7.

Fig.- 9 represents 'a' top perspective view of the present hem-folder as detached from the presserfoot.

Fig. 10 represents asec'tional 'view taken substantiallyalongfthe line lll 'l0 of Fig. 7.

Fig. 11 'represents"a' sectional view taken substantially along'the line l l -1ll"of Fig. 8.

Referring more specifically to the drawings, the invention isshown as embodied in an overedge sewing machine of the typedisclo'sed in the U. S. Patent of N. Knaus, No. 2,238,796, April 15, 1941.

The present machine has al'main frame comprising a base'fia ne portion I2 and an upstanding portion [3, base portion 12 "carries a horizontally'di'sposed work-supporting plate l4 and a throat plate-I5 l fovide'd with slots (not herein shown)v through which'o'perate serrated feed-dogs l'6l6 forming a part of work-feeding mechanism'hereinaiter referred to. The main frame also supports cveredge stitch-forming mechanism comprising ajreciprocating curved needle l l, and an 'under 'or 'needle-loop-takingthread-carrying looper l8 and an overedge looper or loop spreader [9 'which cooperates with the needle I! and looper l8 in'the'fo'rmation of overedg'e's'titches. The machine-also includes a conventional work-feeding mechanism, designated generally as 20, and a cooperating presser device for advancing the work toand beyond the stitchforming mechanism. The'presser device comprises a horizontally disposed spring-depressed presserbar'zl pivoted at its rear e'ndto the machine frame and carrying, at its forward end, a presser foot 22 which overlies" the serratedfeeddogs l'6-'-l6 which form a part of the Work-feeding mechanism. The machine further includes a trimming mechanism adapted to trim the work at one side of the line'of'seam'formation. The trimmingniechanism includes a vibratory trimmerbar 23 actuatedifrom the main shaft of the machine ndcarr in at its-forwardend, a movable trimmer-bladefu" which cooperates with a stationary triinrner bl'a'de 25 carried by the base portion of theiniachineffraine. Inasmuch as the specific constructions of the'Stitch-fdrming, workfeeding and work trim'ming mechanisms are shown in the above mentioned patent and form no part of theprese'nt invention, further illustration and description thereof is deemed unnecessary. v p v As hereinabove indicatedyand referring to Figs. 3, 4 and 5, this invention-relatesprimarily to improved means; embodied in a machine of the type above described, for so presenting a workpiece 26 to the stitch-forming mechanism that the marginal portion of the work is folded into flattened S-shape, with the uppermost portion 21 thereof trimmed substantially in vertical alignment with the lowermost fold 28. The needle thereupon penetrates the upper ply 21, adjacent the trimmed edge 29 thereof, and passes through the underlying fold 28 entering and emerging from the same face of the work. The loopers l8 and IS cooperate with the needle H to form an overedge seam 30 which covers the trimmed edge 29 and secures the hem to the body of the fabric by so-called blind-stitching. When hemming either tubular or fiat work, it is desirable that the hem-folder be permitted to have a slight rising and falling movement in its operative position. This movement permits the folder to adapt itself to variations in the thickness of the work such, for example, as when a cross-seam is passing through the folder, and it also permits the folder to rise and fall with the work under the action of the feed-dog.

Cooperating with the present hem-folder is an edge-guide comprising a horizontally disposed block 3| mounted for horizontal floating movements on a saddle, not herein shown, which is mounted upon the lower frame l2. The guide block 3| is formed with a vertically disposed edgeguiding face 32 which engages and guides that portion 28 of the work-piece which is folded about the work-folding blade or arbor of the hemfolder. In addition to its bodily movements transversely of the line of seam formation, the guide block 3| is adapted to have pivotal movements about a vertical axis. Thus, the guide block 3| is mounted to have pivotal and bodily floating movements in a horizontal plane to facilitate the passage and guidance of a workpiece having an irregular folded edge, such, for example, as one having a cross-seam. A floating edge guide of this general nature is disclosed, in more detail, in the United States patent of Knaus, No. 2,434,619, January 13, 1948. It is to be noted that the edge guide 3| and the mount thereof are supported by the base l2 below the level of the work, while the hemfolder which cooperates with the edge-guide is supported above the level of the work thereby providing an unobstructed passageway for the Work.

The present hem-folder is adapted to be secured upon the sewing machine presser-foot 22 which is best disclosed in Figs. 1, 6, 7 and 8. This presser-foot comprises an elongated sole-plate 33 which is provided in its upper portion with a groove 34 for receiving therein the depending portion 35 of the presser-bar 2| about which the presser-foot is pivotally mounted. The presserfoot 22 is maintained in its pivotal relation relative to the presser-bar by means of an arm 33 secured to the presser-foot by means of a screw 31. Referring particularly to Fig. 6, it will be noted that the arm 36 extends rearwardly so as to overlie a laterally extending .portion 38 of the presser-bar thereby to provide a pivotal connection between the presser-bar and presserfoot. Projecting upwardly from the forward end of the sole-plate 33 is an inclined presser-foot toe 39, the upper portion of which is provided with a groove 40 which is disposed crosswise of the presser-foot and of the direction of work feed. As will hereinafter be described, this groove 40 is adapted for receiving therein the present hem-folder device. For a more complete description of a presser mechanism of the present type, reference may be had to the United States patent of Knaus, No. 2,419,494, April 22, 1947.

The present hem-folder includes a horizontally disposed U-shape wire member including upper and lower limbs 4| and 42, of which the lower limb 42 enters between the plies of the folded work and holds the folded right-hand edge 23 of the work against the floating edge guide 3| hereinabove described. The left-hand folded edge 43 of the work engages the crotch portion 44 of the U-shape wire member. More specifically, the present hem-folder comprises a length of wire which is bent intermediate its two ends into a substantially U-shape member including the above noted upper and lower limbs 4| and 42, which member receives the inner fold 43 of the work-piece. The free end portion of the upper limb 4| is bent into a second U-shape member including limbs 4| and 45, which member defines a plane disposed at right angles to that plane defined by the first U-shape member. .In this latter connection, it will be observed that the limbs 4| and 42 of the first U-shape member are disposed in substantial parallelism with the plane defined by the lower or active face of the presser-foot 22. The end portion of the upper limb is bent into a loop 46 which, as is best disclosed in Figs. 6 and 7, is received within the cross groove 40 of the presser-foot toe 39. The screw 41 threaded into the toe 39 functions, in cooperation with a washer 41' to lock the loop 46 of the hemmer, device into a fixed position relative to the presser-foot. Thus, the entirehem-folder device is supported upon the toe 39 of the presser-foot.

The free end portion of the lower limb 42 is bent at right angles to the plane defined by the first U-shaped member and forms an arbor 48 about which theouter fold 28 of the work-piece is wrapped. This arbor 48 is bent backwardly from the first U-shaped member in the line of seam formation and, as is best disclosed in Figs. 7 and 8, it terminates at a location directly beneath the upwardly inclined toe portion 39 of the presser foot. Thus, this wire hem-folding unit is. carried entirely by the presser-foot and after it is properly adjusted relative to the foot, by means of the screw 41, it forms a rigid and integral part of the foot. By loosening the screw 41, however, the wire unit may be shifted back and forth transversely of the direction of workfeed so that the operator may be permitted to adjust the folder so as to produce the desired type of work.

Referring particularly to Figs. 7 and 10, it will be observed that the arbor portion 48 of the hemfolder is slabbed at its upper and lower portions 49 and 50 so as to give a tapered effect to the arbor in order to facilitate the passage of the work thereabout. Also, it will be observed from Figs. 10 and 11 that the lower surface 5| of the lower limb 42 is slabbed so as to reduce the diameter of the lower limb in order to facilitate the passage of the work thereabout.

By mounting the present hem-folderwire upon the presser-foot, an integral unit is produced which, in response to the actions of the feed-dog, will pivot about the presser-bar and facilitate the passage of the work therethrough. Also, it will be appreciated that as variations occur in the work, such as due to cross-seams, the present folder device will be permitted to move up and down with the presser-foot so as to properly accommodate such work.

Referring particularly to Figs. 2 and 6, it will cooperate 'p'roperly'to control the'rightharld "fold "28 ofthe'work material.

"'As best disclosed 'inFigs. "2"'to sgineio'sive, the work 'piece is adapted to" passover the "workfs'upporting 'plate "H and (has its marginal =p-ortion folded intoflattened'S-shape andpasses to the trimming and stitch foi'miiig mechanisms by the combined action of the hem-folder and the edge-guide 3|. That portion 29 of the workpiece which extends to the right beyond the lower fold 28 is trimmed off by the trimming mechanism, as is also the thread-chain which is formed preparatory to the sewing of a tubular article.

Those skilled in the art will readily appreciate that the present wire hem-folder is most inexpensive of manufacture yet at the same time it presents a device which is most efiicient in use. present hem-folder, including the wire member and. the presser-foot, may be applied as a unit to the conventional type of overseaming machine without the necessity of any special fittings in the way of clamps, brackets or bolts. Also, the wire hem-folder portion of the attachment may be removed from the presser-foot whenever it is desired to produce conventional type of stitching on the machine. In other Words, the present invention requires no special fittings which would interfere with the normal use of the sewing machine. Thus the present invention is adapted to be economically exploited.

Referring to Figs. 6 and 9, it will be observed that the upper limbs AI and 45 of the wire hemfolder are formed as a substantially U-shaped member. Also, it will be observed that this U- shaped member extends over and beyond the active portion of the edge-guide 3|. Thus, the crotch portion 52 of this second U-shape member functions in conjunction with the limbs M and 45 to uncurl or flatten the extreme righthand or selvage edge portion of the work as is perhaps best illustrated in Fig. 2. Furthermore, by referring to Fig. 6 it will be appreciated that this second U-shape member permits an operator to attach to the work-piece various additional elements such as shoulder straps, which shoulder straps may be dropped onto the work through this second U-shape member. Thereafter these straps will be trimmed and secured to the work by the stitches in the usual fashion. This attaching of shoulder straps, of course, cannot be produced on any of the prior art devices for the simple reason that no access may be had to the edge-guide at a point beyond the front active portions thereof. In other words, in hemfolders heretofore employed it has been impossible to insert shoulder straps or similar elements through the folder due to the presence of the left-hand edge-guiding portion.

From the above, it will be understood that the present device is not only most efficient in use but at the same time it presents a unit which may be most economically manufactured and exploited commercially.

Having thus set forth the nature of the invention, what we claim herein is:

1. A sewing machine hemming attachment comprising, a presser-foot including an elongated sole-plate, and a toe projecting from the forward end of and being inclined relative to said Furthermore, it will be appreciated that the 'sol'eplateg and a worlafolding 'membenlincldding a -lengthof wireibent -interinediateits two erids into a "substantially -U shap'ed A member wh'ose two limbs exterfd in parallelismwith other 'an transversely' of d*so1e=p1ate, the spacing between such tw bs being substantially 'bne quarter "of an unch one of s'afd limbs :"being secured to the prsser foot toe so as to' support the entire wire thereby, and the free end portion of "the 'otherlimbbeiiig'bent at right angles to'tnebddy-eortion ofsuch" limb and extending lengthwise of and terminating beneath the inclined presser-foot toe.

2. A sewing machine hemming attachment comprising, a presser-foot including an elongated sole-plate, and a toe projecting from the forward end of and being inclined relative to said sole-plate, and a work-folding member including a length of wire bent intermediate its two ends into a substantially U-shaped member whose two limbs extend transversely of said soleplate, the free end portion of one of said limbs being bent out of the plane defined by the U and being adjustably mounted upon and crosswise of the presser-foot toe, and means for releasably locking said free end portion in selective fixed position relative to said presser-foot, and the free end portion of the other limb being bent at right angles to the plane defined by the U and extending lengthwise of and terminating beneath the inclined presser-foot toe.

3. A sewing machine hemming attachment comprising, a presser-foot including an elongated sole-plate, and a toe projecting from the forward end of and being inclined relative to said sole-plate, and a work-folding member including a length of Wire bent intermediate its two ends into a substantially U-shaped member whose two limbs are disposed in substantial parallelism with the plane defined by the bottom surface of said sole-plate and with the plane defined by the two limbs disposed at right angles to the plane defined by the bottom of said soleplate, the free end portion of one of said limbs being bent into a second U-shaped member which defines a plane disposed at right angles to the plane defined by the first U-shaped member, the end of such first mentioned limb being secured to the presser-foot toe, and the other limb of said first U-shaped member being bent at right angles to the plane defined by the first mentioned U-shaped member and being disposed with its end beneath the inclined toe.

4. A sewing machine hemming attachment comprising, a presser-foot including an elongated sole-plate, a toe projecting from the forward end of and being inclined relative to said sole-plate, said toe being provided with a slot defining a flat platform formed crosswise of and within the upper forward portion of said toe, and a work-folding member including a length of wire bent intermediate its two ends into a substantially U-shaped member whose two limbs are disposed in substantial parallelism with the plane defined by the bottom surface of said soleplate and with the plane defined by the two limbs disposed at right angles to the plane defined by the bottom of said sole-plate, the free end portion of the upper of said limbs being bent into a second U-shaped member which defines a plane disposed at right angles to the plane defined by the first U-shaped member, the end of said first mentioned limb being disposed upon said presser-foot platform and crosswise of said presser-foot sole-plate, a screw threaded into 7 said platform and r'eieasably engaging the free U-shaped end portion of said first mentioned limb so as to lock such limb in selective positions of adjustment crosswise of said sole-plate, and the other limb of said first U-shaped member being bent at right angles to the plane defined by the first mentioned U-shaped member and being disposed with its end beneath the inclined toe.

NICHOLAUS KNAUS. AGNES G. MILLING'I'ON.

8 References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Simons' Nov. 23, 1897 Goforth et a1 Mar. 4, 1902 Merrow Apr. 28, 1914 Briggs et a1. Aug. 11, 1931 Washburn Jan. 2, 1934 Washburn Feb. 25, 1941 Knaus et a1 Jan. 13, 1948 

